Nippon Decimal Classification
The Nippon Decimal Classification (NDC, also called the Nippon Decimal System) is a system of library classification developed for mainly Japanese language books maintained by the Japan Library Association since 1956. It is based on the Dewey Decimal System. The system is based upon using each successive digit to divide into nine divisions with the digit zero used for those not belonging to any of the divisions.
The system is made up of ten categories: